Dynamic Processes in the Atmosphere Determining Summertime Precipitation Anomalies in the Western Siberia and Mongolia

Antokhina, O. Yu.; Antokhin, P. N.; Devyatova, Elena; Mordvinov, Viatcheslav A.

doi:10.21513/2410-8758-2018-1-10-27

Cited by 7 publications

(2 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Beginning of this period refers to the mid-1990s of the 20th century [4,5]. It was found out that the low water in Baikal is due to long-term decrease in the amount of precipitation falling out in summer in the basin of the Selenga River [6][7][8][9]. As one of the main reasons for variations in rainfall in the Selenga basin, authors of [7][8][9] consider the activity of summer blockings in Eastern Siberia, in particular, and in the Eastern hemisphere in general.…”

Section: Discussionmentioning

confidence: 99%

Long-Term Cloud Cover Variations within the Region of Optical Observatories in the South of Eastern Siberia

Devyatova

2020

Proceedings of the 3rd International Electronic Conference on Atmospheric Sciences

View full text Add to dashboard Cite

In the south of Eastern Siberia (Russia), there are optical observatories of the Institute of Solar-Terrestrial Physics SB RAS. The observatories are equipped with instruments to observe the Sun, near and deep space. The first one, Sayan Solar Observatory, is located in the mountains at the height of 2,000 m (51.67 N, 100.99 E). The second, Baikal Astrophysical Observatory, is on the southern bank of Lake Baikal (51.86 N, 104.86 E). These two observatories were built in the 60s-70s of the last century. The purpose of this work is to study the long-term dynamics of cloud cover within the region of the optical observatories. We used data of: Monthly mean Total cloud cover (TCC), High cloud cover (HCC), Low cloud cover (LCC) and Medium cloud cover (MCC) values derived from ECMWF ERA-Interim 1979-2018 [1] and Monthly mean TCC values derived from NCEP/NCAR Reanalysis Gaussian Grid 1948-2019 [2]. Both reanalysis projects show a long-term decline in the annual TCC values. For the summer season, negative trend is most obvious and typical for HCC, MCC, and LCC. In our opinion, the causes of the current changes should be searched for in the peculiarities of long-term variability of large-scale atmospheric circulation, particularly, in blocking activity.

show abstract

Section: Discussionmentioning

confidence: 99%

Long-Term Cloud Cover Variations within the Region of Optical Observatories in the South of Eastern Siberia

Devyatova

2020

Proceedings of the 3rd International Electronic Conference on Atmospheric Sciences

View full text Add to dashboard Cite

show abstract

“…In both periods, typical structures of dipole blocking over Eastern Siberia and Mongolia correspond to ESM-blocks. Analysis of some ESM blocking events has shown that the cyclonic parts of ESM-blocks are characterized by advection of air masses from the East Asian monsoon region (EASM) [42]. Analysis that has been provided by Chen et al 2017 [43] indicated that there is a close relationship between the midlatitude summer cyclone activity over East Asia and the decadal variation of EASM; when the midlatitude summer cyclone activity over East Asia is strong (weak), EASM tends to be intensified (weakened).…”

Section: The Change Of European Blocking and Precipitation In The Rusmentioning

confidence: 99%

The Linkage of the Precipitation in the Selenga River Basin to Midsummer Atmospheric Blocking

et al. 2019

View full text Add to dashboard Cite

The linkage between atmospheric blocking (blocking frequency, BF) and total monthly July precipitation in the Selenga River Basin, the main tributary of Lake Baikal, for the period 1979–2016 was investigated. Based on empirical orthogonal functions (EOF) analysis, two dominant modes of precipitation over the Selenga River Basin were extracted. The first EOF mode (EOF 1) is related to precipitation fluctuations mainly in the Mongolian part of Selenga; the second EOF mode (EOF 2)—in the Russian part of Selenga. Based on two different modes obtained, the total amount of precipitation individually for the Russian and Mongolian part of Selenga was calculated. Correlation analysis has demonstrated that precipitation over the Mongolian part of the Selenga Basin is positively correlated to blocking over Eastern Siberia/Mongolia (80–120° E, ESM-BF). Precipitation over the Russian part of the Selenga Basin is positively correlated to blocking over the Urals-Western Siberia (50–80° E, UWS-BF) and European blocking (0–50° E, E-BF). However, the linkage is not stable, and after the mid-1990s, the obtained positive correlation became insignificant. The analysis has shown that the dominance of E or ESM-blocking in July was the primary driver of the existence of two precipitation modes over the Selenga River Basin. During 1996–2016, the negative trend of time coefficients of EOF 1 and 2 for precipitation in Selenga had been observed, which was characterized by displacement of positive precipitation anomalies outside the basin. At the same time, there was a weakening of the linkage between precipitation in the Selenga Basin and blocking frequency. We have revealed two wave-like modes over Northern Eurasia and the subtropical part of Eurasia corresponding to E, ESM-blocks in 1979–1995 and 1996–2016. The change of the Northern and subtropical wave modes is one of the causes for the weakening of the linkage between atmospheric blocking and precipitation in the Selenga Basin and as a consequence decreased precipitation in the Russian and Mongolian part of Selenga during 1979–2016.

show abstract

Precipitation in the Selenga River basin during atmospheric blocking over Europe and the Russian Far East in July

Antokhina

Antokhin

Devyatova

et al. 2018

IOP Conf. Ser.: Earth Environ. Sci.

View full text Add to dashboard Cite

Dynamic Processes in the Atmosphere Determining Summertime Precipitation Anomalies in the Western Siberia and Mongolia

Cited by 7 publications

References 23 publications

Long-Term Cloud Cover Variations within the Region of Optical Observatories in the South of Eastern Siberia

Long-Term Cloud Cover Variations within the Region of Optical Observatories in the South of Eastern Siberia

The Linkage of the Precipitation in the Selenga River Basin to Midsummer Atmospheric Blocking

Precipitation in the Selenga River basin during atmospheric blocking over Europe and the Russian Far East in July

Contact Info

Product

Resources

About